"Simulation" is already supposed to earn a caution (yellow). The problem is it's really hard to tell at game speed what is simulation, and what isn't. Not in all cases-there are instances that are obvious, but more often than not two players are in close proximity, one goes down in a way that is entirely consistent with contact (whether illegal or not), and, ps, running at full speed and having your foot, ankle, or shin kicked or stepped on hurts...a lot. Even if it doesn't cause lasting injury.
There's also a question of what is "simulation" (i.e., there was no contact/foul) and embellishment (as one coach I've heard called it, "helping the referee see the foul").
The Alex Morgan PK against the Netherlands is a good example. A lot of people complained that Morgan was simulating, but on VAR there was enough contact to warrant awarding the foul. And the bruise on her arm showed that she really was drilled on that play.
All that said, the cautions for simulation should come more often than they do. That would help.
PS Morgan "simulates" and embellishes more than most women players.